Why in News?

• According to the Indian Space Research Organisation (ISRO) chairman S. Somanath, the country's first solar mission - Aditya-L1 mission, is likely to be launched by June-July this year.
• He was speaking at the handover ceremony of the Visible Line Emission Coronagraph (VELC) payload - one of seven payloads (instruments) on board Aditya – L1. 

What’s in Today’s Article?

• What is the Aditya-L1 Mission?
• News Summary with respect to the Aditya-L1 Mission

What is the Aditya-L1 Mission?

• Aditya (in Sanskrit means Sun) is a planned coronagraphy spacecraft to study solar atmosphere (solar corona - outermost part).
• It is currently being designed and developed by ISRO and various other Indian research institutes.
• First dedicated Indian mission to observe the Sun, it is planned to be launched in June-July 2023 aboard a PSLV-XL launch vehicle.
  • It was conceptualised in 2008 and was initially envisaged as a small 400 kg satellite.
• The mission's objectives have subsequently been broadened and it is now intended to be a comprehensive observatory of the sun and space environment.
• It will be placed in an orbit around the Lagrange (L1) point (L1 is about 1.5 million kms from Earth) between Earth and the sun (so renamed - "Aditya-L1").
  • Lagrange points are positions in space where objects sent tend to stay there, as the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.
  • These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.
  • The first Lagrangian point of the Sun-Earth system, L1 orbit, allows Aditya-L1 to look at the Sun continuously.
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• The spacecraft will study coronal heating, solar wind acceleration, coronal magnetometry, origin and monitoring of near-UV solar radiation.
  • It will continuously observe photosphere, chromosphere and corona, solar energetic particles and magnetic field of the Sun.

News Summary with respect to the Aditya-L1 Mission:

• In total Aditya-L1 has seven payloads, of which the primary payload - the VELC, is designed and fabricated by the Indian Institute of Astrophysics (IIA, Bengaluru).
  • The payload will be taken to the R. Rao Satellite Centre (Bengaluru), where it will be integrated with the Aditya-L1 satellite and will undergo further testing, evaluation and finally launched using the PSLV.
  • The VELC payload will observe the corona continuously and the data provided by it is expected to answer many outstanding problems in the field of solar astronomy.
  • No other solar coronagraph in space has the ability to image the solar corona as close to the solar disk as VELC can (can image it as close as 1.05 times the solar radius).
  • It can also do imaging, spectroscopy, and polarimetry at the same time, and can take observations at a very high resolution.
• The other six payloads are being developed by the ISRO and other scientific institutions.
• Understanding the effect of the Sun on the Earth and its surroundings has become very important now and Aditya-L1 aims to shed light on this topic.